Effect of solid-state fermentation with Bacillus pumilus on the nutritional value, anti-nutritional factors and antioxidant activity of faba bean (Vicia faba L.) meal

Abstract

To improve the utility value of faba bean meal (FBM), the effects of solid-state fermentation (SSF) by a strain of Bacillus pumilus on nutritional value, in vitro protein digestibility, anti-nutritional factors (ANFs), flavonoid, phenols and antioxidant activity were evaluated. The results revealed that the concentrations of ANFs (phytic acid and proanthocyanidin) were significantly decreased (P < 0.05) after fermentation. Fermented FBM showed higher nutritional value. Crude protein, amino acids and trichloroacetic acid-soluble protein contents in fermented FBM were higher than those from unfermented FBM. Meanwhile, the contents of phenols and flavonoid were remarkably (P < 0.05) increased after SSF. Scanning electron microscope showed that the surface of fermented FBM was more irregular and rougher than unfermented FBM. Moreover, SSF treatment significantly (P < 0.05) increased DPPH and superoxide anion radical scavenging capacities. The results indicated that SSF of FBM with B. pumilus is a promising and efficient method to improve nutritional value and antioxidant activity, as well as decrease the concentration of ANFs, which also endow the potential value of FBM on replacing soy bean as primary protein source in the feed ration of different animals.